中文摘要：

降雨在节理岩体的离散元模拟中有一定的局限性。文章提出一种等效渗流法模拟降雨条件下地下水向坡脚的渗流过程。以西南地区某顺层岩质滑坡为例,采用施加固定水头的方法,实现地下水在滑体内部的渗流过程,从而诱发滑坡形成。研究结果表明：（1）雨水入渗从坡顶向坡脚渗流,导致滑体内部空隙水压力升高;（2）斜坡受地下水渗流影响,坡脚首先发生变形并逐渐向上部呈阶梯状扩展。随渗流时间的延长,坡脚产生滑移,斜坡中上部和后缘出现拉裂,沿软弱夹层发生整体向河流方向滑动堆积形成堰塞湖;（3）滑坡形成的地质力学模式为＂滑移-拉裂＂,滑体前缘运动至河流对岸形成前缘鼓丘,模拟结果与现场实际特征吻合。该方法可实现降雨条件下节理岩质斜坡中地下水渗流对滑坡形成的影响模拟。

英文摘要：

Rainfall has some limitations in the simulation of discrete joints. This paper presents a method of equivalent seepage to simulate the seepage process of groundwater to the slope toe after rainfall. Taking a bedding rock landslide in southwest China as an example, the authors used the fixing head of groundwater in the slope to simulate the seepage process within the sliding body. The seepage trigger mechanism of the landslide was obtained. The results show that （1） seepage from top to toe in the slope leads to the increase in the interstitial hydraulic pressure within the sliding body. （2） Affected by the traction of groundwater, deformation first occurs at the toe of the slope, then extends to the upper part in the shape of stairs. Along with the growth of the groundwater seepage time, the slope toe begins to slip, the upper part and the trailing edge begin to generate cracks. The whole slope finally slides toward a river along the weak interlayer and forms a dammed lake. （3） The formation mechanism of the landslide is shear slipping-tension cracking. The toe of the slide body moves to the opposite side of the river and forms a drumlin. The simulation results are in agreement with the actual characteristics of the field. This method can be used to simulate the influence of groundwater movement on the slope stability under the condition of rainfall.